The specific aim of this project is to conduct a study of the feasibility of two innovative methods of non-linear dynamical analysis for obtaining useful information from demographic. These two methods: 1) fractal scaling of relative dispersion and 2) recurrence plots. The demographic data to be analyzed are in the form of a time series of the daily number of births to young women 10 to 19 years old in Texas from 1980 through 1997. There is convincing evidence to suggest that the proposed methods will enable researchers to obtain more accurate and complete descriptions of data than are now possible with traditional approaches. However, a rigorous feasibility study is warranted to evaluate the reliability and validity of these methods for demographic analysis in a variety of applications. Each of the methods will be evaluated for its ability to: a) discriminate among experimental data sets of known dynamical structure; b) detect different dynamical features in time series from cities and regions in Texas with varying demographic characteristics, number and rate of teen births and percentage of out-of-wedlock teen births; and c) provide a more accurate and complete description of changes in the dynamics of the time series for Texas coincidental and lagged with events intended to alter reproductive behaviors or outcomes among teens. Such events will include the Adolescent Family Life Act (Chastity Bill) in 1981, Medicaid reimbursement approval for Norplant in Texas in 1992 and the Welfare Reform Act of 1996. Reducing pregnancies in young women, under 18, through family planning, is one of 22 priorities included in Healthy People 2000. Texas is one of five states in the United States in which teen pregnancies exceed 70 per 1000 females aged 15-17. The goal is to have fewer than 50 per 1000. The approach proposed will address this serious public health concern by introducing innovative methods of analysis of the existing problem. Through more complete and accurate analysis, more effective policy, and interventions can be designed, implemented and evaluated.